Thionyl Chloride → 4-(4-Dimethylcarbamoyl-3-fluoro-phenoxy)-2,2-dimethyl-2,3-dihydro-benzofuran-6-carboxylic acid (5-methyl-isoxazol-3-yl)-amide

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Reaction Conditions

Reaction Steps

To a solution of 4-(4-dimethylcarbamoyl-3-fluoro-phenoxy)-2,2-dimethyl-2,3-dihydro-benzofuran-6-carboxylic acid (143a) (66 mg, 0.177 mmol) in 3 mL of CH2Cl2 was added thionyl chloride (0.0154 mL, 0.212 mmol), followed by 3 drops of DMF. The mixture was refluxed for 1.5 h, then concentrated and dried under vacuum. The residue was dissolved in 3 mL of CH2Cl2, added 3-amino-5-methylisoxazole (22.6 mg, 0.230 mmol) at 0° C., followed by DMAP (52 mg, 0.354 mmol). The mixture was stirred at 0° C. to room temperature for 1 hr and heated at 40° C. overnight, then concentrated and purified by flash column chromatography with 40-55% EtOAc in hexanes to give a white solid (8 mg, 10% yield). 1H NMR (400 MHz, CDCl3) δ 9.06 (s, 1 H) 7.38 (t, J=8.08 Hz, 1 H) 7.11 (d, J=1.77 Hz, 2 H) 6.76-6.84 (m, 2 H) 6.70 (dd, J=10.61, 2.27 Hz, 1 H) 3.13 (s, 3 H) 2.98 (br. s., 3 H) 2.91 (s, 2 H) 2.42 (s, 3 H) 1.50 (s, 6 H); LCMS for C24H24FN3O5 m/z 454.00 (M+H+).

Provenance & Evidence